Employee Benefit Plans and Stock-based Compensation - Summary of Projected Benefit Obligation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018
Employee Benefit and Share-based Payment Arrangement, Noncash Expense [Abstract]
Service cost	$ 57	$ 59	$ 171	$ 185
Interest cost	20	18	59	56
Net periodic benefit cost	$ 77	$ 77	$ 230	$ 241